A rally for on-highway diesel prices has ended with the average cost of the fuel falling for the first in more than a month, according to the latest weekly report from the U.S. Energy Department, as the price of crude oil is down dramatically.

The national average cost of on-highway diesel has posted its fifth weekly increase but prices have started to moderate a little in some parts of the country, according to new U.S. Energy Department figures.

Despite the first upturn since November in average diesel prices this week, expect prices to move slightly lower at least for a while longer, according to the U.S. Energy Department and its latest Short-Term Energy Outlook released on Wednesday.

In the wake of diesel prices falling from an average of more than $4 per gallon nearly a year ago the U.S. Energy Department's Energy Information Administration has lowered its price forecast from last month’s prediction.

The U.S. Energy Department reported Monday the average U.S. price for on-highway diesel fell another 8,4 cents over the past week to $3.053 per gallon. This is the lowest price since October 2010 and is 83.3 cents less than the same time last year

The average price of on-highway diesel continued falling into final week of 2014, down significantly from its high for the year and hitting its lowest price since December 2010, according to the U.S. Energy Department.

Since the summer, the price of oil has plummeted 50 percent, hitting its lowest level in more than five years about a week before Christmas. Diesel has fallen from a yearly high of $4.021 in March to $3.419 in mid-December.